Conventionally, there have been MIMO (Multiple-Input Multiple-Output) technologies (see, for example, Non-Patent Document 1).
Conventionally, there have also been technologies in which sending-side precoding is carried out by MIMO (see, for example, Non-Patent Document 2).
Non-Patent Document 1: G. J. Foschini, Bell Labs Tech. J, pp. 41-59, Autumn (1996)
Non-Patent Document 2: Andre Bourdoux, Nadia Khaled, VTC 2002-Fall. IEEE 56th pp. 171-174, 1 (2002)